1. Field of the Invention
The present invention relates to a mobile terminal having a multimedia data service function, and more particularly, to a method of controlling the operation of a mobile terminal having a multimedia data service capability. The method according to the present invention can significantly reduce power consumption of the mobile terminal and the communication cost when using a multimedia data service such as a Video-on-Demand (VOD) service.
2. Background of the Related Art
A Video-on Demand (VOD) service can provide multimedia data such as motion picture data to many users widely dispersed at same time. The VOD service technique can be applied to many interactive multimedia data service fields such as Movies-on-Demand service, interactive video games, news, advertisements, product catalog search, remote education, video conference, digital library, and multimedia intranet services and more.
FIG. 1 is a block diagram of a code division multiple access (CDMA) mobile terminal having a VOD service function according to the related art. According to FIG. 1, the mobile terminal includes a duplexer 150 for receiving/transmitting signals through an antenna (ANT), a signal transmitting/receiving (T/R) part 100 for transmitting/receiving signals to/from a base station, a signal processing part 300 for performing necessary processes on the incoming or outgoing signals, a memory part 400 for storing the signals processed in the signal processing part 300, a data generator 200 for generating sound/image signals from the signals processed in the signal processing part 300 and playing-back the sound/image signals through a display unit 250 and a speaker 220, and a power supply 500 for providing power (electricity) to the signal T/R part 100 or signal processing part 300.
In addition, the signal T/R part 100 of the mobile terminal includes a baseband transmitter 110 for generating baseband signals based on the signals received from the signal processing part 300, a radio frequency (RF) transmitter 120 for transmitting the baseband signals to an outside receiving system through the duplexer 150, a radio frequency (RF) receiver 130 for receiving the RF signals from an outside transmitting system through the duplexer 150, and a baseband receiver 140 for processing the RF signals received from the RF receiver 130 and sending the processed signals to the signal processing part 300.
Moreover, the data generator 200 includes a voice Coder-Decoder (CODEC) 210 for coding the analog voice signals and decoding digital voice signals processed from the signal processing part 300, a speaker 220 for generating sound based on the sound signals decoded in the CODEC 210, a microphone 230 for receiving the voice signals of a telephone user, an image CODEC 240 for decoding the image signals processed in the signal processing part 300, and a liquid crystal display (LCD) 250 for displaying the image signals decoded in the image CODEC 240.
Reference will now be made in detail to the CDMA mobile terminal having a VOD service function according to the related art. When the power of the mobile terminal is on initially, the signal processing part 300 controls the power supply 500 in order to provide necessary power to the signal processing part 300 and the signal T/R part 100 of the mobile terminal. The antenna (ANT) receives the RF signals from a base station and transmits the received signals to the signal T/R part 100 through the duplexer 150. The RF receiver 130 then receives the RF signals and sends the signals to the baseband receiver 140 to generate baseband signals. When the signal processing part 300 receives the baseband signals, the status of the mobile terminal turns to a paging state. In other words, the mobile terminal becomes aware of the fact that the VOD signals are being received.
Next, the signal processing part 300 sends the status information of the mobile terminal including an ESN (electrical serial number) and others to the base station. When the base station registers the mobile terminal (MT), the status of the MT turns to a standby state, and it checks whether there was a VOD service request made by a telephone user. This is done by checking whether the user switched the status of the MT to a traffic state by pressing down the prescribed telephone keys. If there was a request made by the user, the signal processing part 300 then sends a VOD service request signal to the base station and receives corresponding VOD data through the signal T/R part 100.
Next, the signal processing part 300 performs the required processes on the VOD data received. The voice CODEC 220 decodes the voice signals and outputs them through a speaker 220, and the image CODEC 240 decodes the image signals and displays them on the LCD 250. Finally, when the signal processing part 300 receives all the VOD data, it terminates the line connection and the VOD service.
The problems due to limitations and disadvantages of the CDMA mobile terminal having a VOD service function according to the related art are as follows. First, the status of the mobile terminal remains unchanged while it receives and plays-back the VOD data. Therefore, the user will be responsible to pay the communication charges even after the data transmission is completed. It also means that the power will still be provided to each element of the signal T/R part (110, 120, 130, and 140) during such period of time. Therefore, it shortens the battery life of the mobile terminal.